Question #52580

1 Answer
Nov 20, 2017

"200 g MgCl"_2

Explanation:

The first thing that you need to do here is to figure out how many grams of magnesium chloride would be produced by the reaction at 100% yield.

To do that, use the molar mass of magnesium chloride

3 color(red)(cancel(color(black)("moles MgCl"_2))) * "95.211 g"/(1color(red)(cancel(color(black)("mole MgCl"_2)))) = "285.63 g"

This means that at 100%yierld, you would expect the reaction to produce "285.63 g" of magnesium chloride.

However, you know that the reaction has a 73% yield, which means that for every "100 g" of magnesium chloride that the reaction could theoretically produce, you only get "73 g".

You can thus say that your reaction will produce

285.63 color(red)(cancel(color(black)("g MgCl"_2color(white)(.)"in theory"))) * overbrace(("73 g MgCl"_2 color(white)(.)"produced")/(100color(red)(cancel(color(black)("g MgCl"_2color(white)(.)"in theory")))))^(color(blue)("= 73% yield"))

= color(darkgreen)(ul(color(black)("200 g MgCl"_2color(white)(.)"produced")))

The answer is rounded to one significant figure, the number of sig figs you have for the number of moles of magnesium chloride that would be produced at 100% yield.